How great would it be if Bethesda formed some sort of partnership with Last.fm to stream 50's and 60's music into the Pip-boy radio? They could even have certain genres streamed into certain stations (50's country into Black Mountain Radio, for example) and with hundreds of different songs to choose from, the problem of the tedium of hearing Johnny Guitar 400,000 times becomes nonexistent, and MASSIVELY improves the atmosphere and usability of the radio stations. This also wouldn't be the first a video game company teamed with an outside business to improve the game, EA Sports and the Weather Channel joined to load the real-life weather conditions of football stadiums into the game's digital counterpart.
If I could pick one feature to be added to the next Fallout, it would most definitely be this.